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Medium

Discourse Has Denial of Service (DoS) Vulnerability in Drafts Creation Endpoint

Type: advisorySources: OSV

Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, authenticated users can submit crafted payloads to /drafts.json that cause O(n^2) processing in Base62.decode, tying up workers for 35-60 seconds per request. This affects all users as the shared worker pool becomes exhausted. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. Lowering the max_draft_length site setting reduces attack surface but does not fully mitigate the issue, as payloads under the limit can still trigger the slow code path.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2025-68934
Confirmed fixed CVEs
Not specified
Updated in this feed
4 Nov 2026, 07:45 UTC · Revision 1

Source evidence

Discourse Has Denial of Service (DoS) Vulnerability in Drafts Creation Endpoint

core-osv · Original source

Published 28 Jan 2026, 19:19 UTC

Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, authenticated users can submit crafted payloads to /drafts.json that cause O(n^2) processing in Base62.decode, tying up workers for 35-60 seconds per request. This affects all users as the shared worker pool becomes exhausted. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. Lowering the max_draft_length site setting reduces attack surface but does not fully mitigate the issue, as payloads under the limit can still trigger the slow code path.

osv:CVE-2025-68934
Complete source record
{
  "id": "4a65ce852be772eb7bbf59f6f8ced88d111bd66f9b7584013926ebcf384e5d87",
  "url": "https://osv.dev/vulnerability/CVE-2025-68934",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Discourse Has Denial of Service (DoS) Vulnerability in Drafts Creation Endpoint",
    "summary": "Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, authenticated users can submit crafted payloads to /drafts.json that cause O(n^2) processing in Base62.decode, tying up workers for 35-60 seconds per request. This affects all users as the shared worker pool becomes exhausted. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. Lowering the max_draft_length site setting reduces attack surface but does not fully mitigate the issue, as payloads under the limit can still trigger the slow code path.",
    "evidence": "osv:CVE-2025-68934",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2025-68934",
      "aliases": [
        "BIT-discourse-2025-68934",
        "CVE-2025-68934",
        "GHSA-vwjh-vrx9-9849"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/discourse/discourse",
              "type": "GIT",
              "events": [
                {
                  "introduced": "75d61b40ee928a4620b16f5438ca886678fab00d"
                },
                {
                  "fixed": "f31b18139a7aadbc4a5f7e8e565a6f4376010c3a"
                },
                {
                  "introduced": "3e7317b3344cca6c6510a32cc4c5c0f540132ad9"
                },
                {
                  "last_affected": "322d3c0ac6a8f133b3f82875e9dbbe310f638c1b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*",
                    "range": [
                      {
                        "introduced": "2025.11.0"
                      },
                      {
                        "fixed": "2025.11.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:2025.12.0:*:*:*:stable:*:*:*",
                    "range": [
                      {
                        "introduced": "2025.12.0"
                      },
                      {
                        "last_affected": "2025.12.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:discourse:discourse:2026.1.0:*:*:*:stable:*:*:*",
                    "range": [
                      {
                        "introduced": "2026.1.0"
                      },
                      {
                        "last_affected": "2026.1.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2025.12.0",
            "2026.1.0",
            "v2025.11.1",
            "v2026.1.0-latest",
            "v2025.11.0",
            "v2025.12.0-latest"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-68934.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:33.979234481Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68934.json",
        "https://github.com/discourse/discourse/security/advisories/GHSA-vwjh-vrx9-9849",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-68934"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-770"
        ],
        "cna_assigner": "GitHub_M",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": ">= 2025.12.0-latest, 2025.12.1"
                  },
                  {
                    "last_affected": ">= 2025.12.0-latest, 2025.12.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandaloneSingleVersion"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "3.5.4"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68934.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-68934",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 500933,
  "published_at": "2026-01-28T19:19:59.627+00:00"
}